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    label=<<font point-size="24"><br />Group 1</font>>
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    2 [id=2,shape=rect, label=<<font point-size="34">B</font><br /><font point-size="19">[Software System]</font>>, style=filled, color="#9a9a9a", fillcolor="#dddddd", fontcolor="#000000"]
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      subgraph "cluster_group_Group 3" {
        margin=25
        label=<<font point-size="24"><br />Group 3</font>>
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        fontcolor="#cccccc"
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        4 [id=4,shape=rect, label=<<font point-size="34">D</font><br /><font point-size="19">[Software System]</font>>, style=filled, color="#9a9a9a", fillcolor="#dddddd", fontcolor="#000000"]
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  3 -> 4 [id=12, label=<>, style="dashed", color="#707070", fontcolor="#707070"]
  1 -> 2 [id=9, label=<>, style="dashed", color="#707070", fontcolor="#707070"]
}